The Clark Fork River
The largest river by volume in Montana, it drains an extensive region of the Rocky Mountains in western Montana and northern Idaho in the watershed of the Columbia River. The river flows northwest through a long valley at the base of the Cabinet Mountains and empties into Lake Pend Oreille in the Idaho Panhandle. The Pend Oreille River in Idaho, Washington, and British Columbia, Canada which drains the lake to the Columbia in Washington, is sometimes included as part of the Clark Fork, giving it a total length of 479 miles (771 km), with a drainage area of 25,820 square miles (66,900 km2). In its upper 20 miles (32 km) in Montana near Butte, it is known as Silver Bow Creek. Interstate 90 follows much of the upper course of the river from Butte to northwest of Missoula. The highest point within the river's watershed is Mount Evans at 10,641 feet (3,243 m) in Deer Lodge County, Montana along the Continental Divide.
The Clark Fork is a Class I river for recreational purposes in Montana from Warm Springs Creek to the Idaho border.
The Clark Fork should not be confused with the Clarks Fork of the Yellowstone River, which is located in Montana and Wyoming.
The Blackfoot River
The Blackfoot River, sometimes called the Big Blackfoot River to distinguish it from the Little Blackfoot River, is a snow-fed and spring-fed river in western Montana. The Blackfoot River begins in Lewis and Clark County at the Continental Divide, 10 miles (16 km) northeast of the town of Lincoln (4536 feet, 1382 m). The river's headwaters are between Rogers Pass (5610 ft, 1710 m) to the north and Stemple Pass (6376 ft, 1943 m) to the south. It flows westward through the town of Milltown and enters the Clark Fork River approximately five miles (8 km) east of the city of Missoula (3210 ft, 978 m).
The Blackfoot River is renowned for its recreational opportunities, most notably fly fishing, but also rafting, canoeing, and inner tubing. The Blackfoot is a fast, cold river with many deep spots, making it prime habitat for several varieties of trout.
The Bitterroot River
The Bitterroot River is a northward flowing 84-mile (135 km) river running through the Bitterroot Valley, from the confluence of its West and East forks near Conner in southern Ravalli County to its confluence with the Clark Fork River near Missoula in Missoula County, in western Montana. The Clark Fork River is tributary to the Columbia River and ultimately, the Pacific Ocean. The Bitterroot River is a Blue Ribbon trout fishery with a healthy population of native westslope cutthroat trout and bull trout. It is the third most fly fished river in Montana behind the Madison and Big Horn Rivers.
The Flathead River
The Flathead River in the northwestern part of the U.S. state of Montana, originates in the Canadian Rockies to the north of Glacier National Park and flows southwest into Flathead Lake, then after a journey of 158 miles (254 km), empties into the Clark Fork. The river is part of the Columbia River drainage basin, as the Clark Fork is a tributary of the Pend Oreille River, a Columbia River tributary. With a drainage basin extending over 8,795 square miles (22,780 km2) and an average discharge of 11,380 cubic feet per second (322 m3/s), the Flathead is the largest tributary of the Clark Fork and constitutes over half of its flow.
Rock Creek is a 52-mile (84 km) river in Missoula and Granite County, Montana. Rock Creek is a tributary of the Clark Fork river. The river's headwaters are in Lolo National Forest near Phillipsburg, Montana. The river roughly parallels the Sapphire Mountains and enters the Clark Fork near Clinton, Montana. Sapphires are found along the river. Rock Creek is a popular fly fishing river for locals and destination anglers. It contains rainbow, brown, westslope cutthroat and the threatened bull trout.